DESCRIPTION: (Applicant's Description) Hereditary cancer predisposition has been denoted by the National Cancer Institute as a high priority area of investigation, and the development of a Cancer Genetics Network has been proposed as a critical component of this effort. When established, the Cancer Genetics Network will provide a resource for the study of patients with a family history of cancer, some of which will have documented mutations in the known cancer susceptibility genes. The University of Pennsylvania Cancer Center is extremely well-suited to serve as a contributing member of the Cancer Genetics Network. Barbara Weber, MD, an internationally recognized expert in cancer genetics will serve as the PI. Timothy Rebbeck, PhD, a Co-Investigator, is one of a handful of molecular epidemiologists with expertise in cancer. The University of Pennsylvania meets all basic Network criteria with an established breast cancer family database of more than 1000 families with extensive family, demographic and exposure history, a registry of more than 200 known BRCA1 and BRCA2 mutation carriers, and a registry of more than 3000 patients from the Pigmented Lesion Clinic. Established clinical cancer risk evaluation programs provide ongoing accrual of patients with a family history of breast, ovarian and colon cancer as well as melanoma. Protocols for pre and post testing counseling for individuals who opt for genetic susceptibility testing are in place and have served as models for many developing programs in the US. Mechanisms for the tracking and follow-up of patients are well-established, biological specimens are in hand for many of the individuals in the registries, specimen collection is ongoing, with newly-entered patients, and an informatics system that will interface easily with other Network sites is in place. Unique capabilities at The University of Pennsylvania include a molecular diagnostic laboratory that provides CLIA-approved analysis of BRCA1 and BRCA1 and is establishing protocols for HNPCC testing, a Cancer Center network of community hospitals that refer all patients for consideration of genetic testing, the Center for Bioethics that has been in the forefront of research in genetic testing for cancer susceptibility, and state-of the art communication capabilities with management of both OncoLink (an online resource for all cancer patients that has been nationally recognized for excellence) and the BIC website (a repository for all known BRCA1 and BRCA2 alterations). In addition, the investigators who will direct Network activities at the University of Pennsylvania have an extensive track record of participation in large collaborative studies requiring sharing of specimens and data.